Comparative removal of malachite green dye from aqueous solution using deep eutectic solvents modified magnetic chitosan nanoparticles and modified protonated chitosan beads

Abstract

Adsorption properties of malachite green (MG) dye onto protonated crosslinked chitosan deep eutectic solvent (PCCDES) and magnetic nanosized chitosan deep eutectic solvents (MNCDES) adsorbents were studied. The batch sorption experiment was carried out under various effects such as pH, initial concentration, adsorbent dosage, ionic interference, and contact time. The data shows a pH-dependent trend indicated pH 4 as optimum for dye removal up to 92.69% and 86.55% for MNCDES and PCCDES, respectively. The characterisations were done using scanning electron microscopy, Fourier transforms infrared spectroscopy, X-ray powder diffraction, thermogravimetric analysis, Brunauer-Emmett-Teller, and vibrating sample magnetometer to reveal surface individualise differences, functional group incorporation, phases of crystallinity, pore sizes, and magnetic character, respectively. The reusability of the adsorbents was examined, and the maximum equilibrium capacity of the data analysed with adsorption isotherms show 87.720 mg/L for MNCDES and 78.125 mg/L for PCCDES which fitted well with the Langmuir model for both adsorbents, and the kinetic behaviour was best described by the pseudo-second-order kinetic model.